Solutions such as inks and paints are produced by mixing various ingredients to produce the end product having the desired characteristics of color, consistency and texture. The mixing process is critical to the end result with the mixing rate and duration being two critical parameters in this process. It is, of course, desireable to use the optimum mixing rate or speed as well as the minimum mixing time to produce the desired results. The optimum mixing rate for a given solution depends upon the characteristics of the individual ingredients. Thus, a given mixing rate for a first set of ingredients may not result in optimum mixing of a second set of ingredients, or may require additional mixing time to produce the desired result. Present approaches employ fixed speed mixers for these types of materials thus necessitating different mixers for different materials or in some cases extended periods of mixing when the mixer speed is not adapted for mixing a particular set of ingredients.
In mixing materials such as inks and paints, it is generally desirable to mix as much of the material as possible by filling the mixing container to, or near, its capacity. This frequently results in overflow or spilling of the contents such as in the case of a high mixing speed applied to a thin solution having low consistency. In many cases, optimal mixing of a solution is achieved by starting with a low mixing speed and then increasing the speed as the mixture becomes more thoroughly mixed. This is not possible with current fixed speed mixers.
The present invention addresses the aforementioned limitations of the prior art by providing a variable speed mixer particularly adapted for use with inks and paints which permits the simultaneous mixing of several batches of ingredients at different, fixed mixing rates and which also allows for varying the mixing rate over a wide range of speeds in a continuous manner for each of the batches.